A prospective clinical study of temporal manual small incision cataract surgery

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A Dissertation on

A PROSPECTIVE CLINICAL STUDY OF

TEMPORAL MANUAL SMALL

INCISION CATARACT SURGERY

Dissertation submitted for

M.S. Degree in Ophthalmology

April 2013

THE TAMILNADU Dr. M.G.R. MEDICAL UNIVERSITY

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Dept. of Ophthalmology

Coimbatore Medical College Hospital

Coimbatore

CERTIFICATE

This is to certify that the dissertation entitled “A

PROSPECTIVE CLINICAL STUDY OF TEMPORAL MANUAL

SMALL INCISION CATARACT SURGERY “is a bonafide research

work done by Dr. Vinodhini. K. in partial fulfilment of the requirement

for the degree of Master of Surgery in Ophthalmology.

Prof. Dr. A. Rajendra Prasad,. MS.DO

Date: HOD & Professor, Dept of Ophthalmology

Place: Coimbatore Coimbatore Medical College Hospital.

Date: The Dean,

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DECLARATION

I hereby declare that this dissertation entitled “A PROSPECTIVE

CLINICAL STUDY OF TEMPORAL MANUAL SMALL

INCISION CATARACT SURGERY “is a bonafide and genuine

research work carried out by me under the guidance of Prof. Dr. A.

RAJENDRA PRASAD M.S.,(ophthal),D.O.,HOD & Professor,

Department of Ophthalmology, Coimbatore Medical College & Hospital,

Coimbatore.

Date:

Place DR. VINODHINI K

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ACKNOWLEDGEMENT

It gave me great pleasure and satisfaction in preparing this

dissertation and I take this opportunity to thank everyone who has made it

possible. Firstly, I would to convey my heartfelt gratitude and sincere

thanks to my guide DR. A. RAJENDRA PRASAD, M.S., D.O., HOD &

Professor, Department of Ophthalmology, Coimbatore Medical College

Hospital, Coimbatore, who with his knowledge and experience, has

provided able guidance and constant encouragement throughout the

course of my postgraduate studies and in the preparation of this

dissertation.

It also gives me immense pleasure to thank Dr. ZAIBUNISSA

M.S., D.O., Professor, Department of Ophthalmology, Coimbatore

Medical College Hospital, Coimbatore, who has been a constant source of

inspiration and has motivated me not only in this dissertation but also

throughout my course.

I would like to extend my heartfelt gratitude to Dr J

SARAVANAN M.S., who performed all the surgeries in the study.

Without his goodwill this dissertation would not have been possible. I

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Department of Ophthalmology, Coimbatore for their whole hearted

support throughout.

I would like to express my gratitude to THE DEAN, Prof Dr

VIMALA M.D., Coimbatore Medical College Hospital, Coimbatore for

her able guidance and encouragement. I also thank the administrative

staff of Coimbatore Medical College Hospital, Coimbatore for their help

and permission for carrying out the study availing all the required

facilities in this hospital. I would also like to thank all the staff nurses and

technicians for helping me in this study.

My full hearted thanks to my family, friends and colleagues who

have helped me in all my endeavours, supporting me through all.

Last but not the least; I am most grateful to all my patients for their

kind cooperation, without whom this study would not have been possible.

I pray to almighty for all his blessings.

DATE:

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A PROSPECTIVE CLINICAL STUDY OF TEMPORAL

MANUAL SMALL INCISION CATARACT SURGERY

CONTENTS

PART ONE

INTRODUCTION

EVOLUTION OF CATARACT SURGERY

REVIEW OF LITERATURE

PART TWO

AIM OF THE STUDY

MATERIALS AND METHODS

RESULTS AND OBSERVATIONS

DISCUSSION

SUMMARY AND CONCLUSION

BIBLIOGRAPHY

PROFORMA

KEY TO MASTER CHART

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ABBREVIATIONS

SMC – senile mature cataract

SIMC – senile immature cataract

V/A – visual acuity

UCVA – uncorrected visual acuity

BCVA – best corrected visual acuity

WHO – World Health Organisation

POD – post operative day

SICS – small incision cataract

MSICS – manual small incision cataract

ECCE – Extracapsular cataract extraction

UV-B – ultraviolet B radiation

US – United States

NPCB – National Program for Control of Blindness

IOL - Intraocular lens

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PCIOL – Posterior chamber intraocular lens

ICCE – Intracapsular cataract extraction

CCC – Continuous curvilinear capsulorhexis

PMMA – poly methyl methacrylate

AC – anterior chamber

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INTRODUCTION

Blindness is a major public health problem1. It is a devastating physical

condition with deep emotional and economic implications1. A blind

person loses his or her independence and is prone to experience a sense of

profound loss and depression arising from being plunged into darkness1.

The family directly shares the economic burden and indirectly so does the

community1. Blindness is also associated with lower life expectancy1.

Cataract is responsible for 50% of blindness in the world; the overall

prevalence rate varies from 1 to 4% of the population1. Cataract

prevalence increases with age2. As the world’s population ages,

cataract-induced visual dysfunction and blindness is on increase2.Cataract is a

significant global problem of 21st century2.

The challenges are to prevent or delay cataract formation, and cure that

which does occur2. Cataract occurs early in developing countries

compared to developed countries1. Multiple factors like increasing age,

genetic and environmental factors contribute to cataract formation2. In

addition to these factors diabetes, exposure to oral and topical

corticosteroids, malnutrition and dehydrational states contribute to the

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The increasing age is an important risk factor and prevalence doubles

with each decade of age after 40years according to a data from Australia2.

The age-adjusted prevalence of cataract in India was three times that of

the US, with 22% of Indians of 75-83 years old having visually

significant cataract, compared to 46% of those aged 75-85years in the

US8. In India cataract occurs nearly 14years earlier than in a comparable

study in US2. This adds to the existing backlog of cataract cases due to

exponential population growth and insufficient health-care resources2.

Environmental risk factors can be altered by reducing ocular exposure to

UV-B radiation and stopping smoking2. In India the high incident light

and populations dependent on outdoor agrarian activities vastly limits the

success of these interventions2.

Cataract progresses faster in diabetic patients, more so in diabetic women

than in men5. People with diabetes have an increased risk of cortical and

subcapsular cataract and are also more likely to have early cataract

surgery2. These associations will assume greater importance as diabetes

continues to increase in both developing and industrialized areas2. The

challenge is to design and deliver widespread public health initiatives

aimed at dietary and physical activity education and behaviour change to

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The current 20 million people with severely reduced vision of 3/60 or

worse due to cataract will have swelled to 40 million by the year 20202.

The benefits of cataract prevention are obvious, but unfortunately, the

likelihood of achieving it is remote2.

The cure for cataract is surgery, and is one of the most cost-effective of

all health interventions2. But this is not equally available to all, and the

available surgery does not produce equal visual outcomes2. The need of

hour is comprehensive strategy including preventive measures to avoid

risk factors combined with widespread surgical services capable of

delivering good vision rehabilitation2.

India has the distinction of being the first country in the world to launch a

nationwide National Programme for Control of Blindness quarter of a

century ago30. Cataract surgeries are performed under NPCB30.

Vision 2020 is a global initiative launched by the World Health

Organization in 19991. It is based on the concept that every living person

has a right to sight and aims to eliminate avoidable blindness worldwide

by the year 20201.The Vision 2020 programme was adopted by the

Government of India as a priority area for health development1. Cataract

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The surgical services need to be accessible, affordable and effective of

good vision rehabilitation2. The goals of modern cataract surgery include

restoration of vision as completely and as rapidly as possible while

minimizing complications28. At the same time, the post operative

refractive errors should be neglible28.

Phacoemulsification is now the standard technique as it offers early visual

rehabilitation and better un-aided visual acuity than the conventional

sutured extracapsular cataract extraction 31, 15. However, the high

expenses of instrumentation and requirement of advanced training have

limited the role of phacoemulsification in our country16, 17.

Manual sutureless small incision cataract surgery has emerged as a cost

effective alternative to phacoemulsification in the developing world16.

SICS has the advantage of a self-sealing Sutureless incision with least

surgically induced astigmatism at a low cost15. It is a safe, simple,

consistent, stable, and cost-effective way of cataract removal6.

The technique of small incision cataract extraction has various

modifications and names31. Nonphaco Sutureless cataract extraction,

Mini-Nuc technique, Manual phaco small incision surgery is some of the

names given. Modifications involve the site, size and type of incision and

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Every modification has its own set of advantages and limitations but the

outcome of cataract surgery depends on the selection of appropriate

technique. Each technique is selected according to the case encountered,

the setting, as well as the surgeon's skill and comfort level.

Present study is done to evaluate the efficacy and safety of temporal

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EVOLUTION OF CATARACT SURGERY

The written history of cataract surgery spans around 20 centuries3. The

term “cataract” was introduced by Constantinus Africanus (AD 1018). He

translated the Arabic “suffusion” into Latin “cataracta” meaning

“something poured underneath something” the “waterfall”3.

For more than 20 centuries, couching was the primary method for

dislodging the cataract away from pupil3. The written description came

from our own Indian surgeon Susruta (600 BC) 3. He used two

instruments – a sharp lancet to penetrate the sclera around 4mm temporal

to limbus and a blunt needle passed through the conjunctiva behind the

iris to dislodge the lens. The temporal approach was used as couching

was performed in sitting posture and surgeon facing the patient3. The

surgeon had to be ambidextrous3.

Jacques Daviel, the father of modern cataract surgery introduced the

incisional extraction of the cataract in 17533. He described a planned

extracapsular cataract extraction and he placed the incision in inferior

limbus as patient was operated in seated position3.

The two milestones that occurred in-between 1753 to 1862 changed the

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1. Pierre-Francois-Benzet Parnard shifted the incision site to upper part

of eye and the patient was operated in supine position.

2. Carl Himly introduced pharmacological mydriasis.

The focus of cataract surgeons shifted towards intracapsular cataract

extraction as removing the lens in toto was considered to be safe3.

Many eminent surgeons like Albert Von Grafe (1867), Christiane

(1845), A.Terson (1871) and G. Reuling contributed to this3.

Boston’s Henry Williams introduced suturing of the cataract surgery

wound in 18673. Colonel Henry Smith refined the intracapsular

cataract surgery by employing Indian-Smith manoeuvre, a sliding

method to tumble the lens into anterior chamber in 19263.

Lens extraction methods changed with the introduction of various

forceps like Veerhoff forceps, Kalt smooth forceps and Arruga’s

capsular forceps3. Ignacio Barraquer (1917) performed phacoerysis

with pneumatic forceps3.

The next breakthrough came by chemical zonulolysis with alpha

chymotrypsin by Jose Barraquer in 19583. Cryoextraction

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was introduced by T. Krawawicz and refined by other surgeons like

Richard Brubaker and David Worhten3.

Harold Ridley introduced artificial lens IOL implantation in 19493.

Between 1965 and 1972, Cornelius Binkhorst modified the IOL

concept. He refined ECCE and used a IOL with two or four loops for

support3. In 1977 Worst devised the “Worst Medallion” IOL, required

suture fixation to iris and two loops through pupil resting on posterior

capsule. This model was used in ICCE cases3. Modern PCIOL was

devised by S P Shearing with J loops.

The era of intracapsular cataract extraction came to an end with the

introduction of intra ocular lens implantation. The need for safe

scaffolding for IOL shifted the focus towards extracapsular cataract

extraction. The other additional influencing factors are the quest for

small incisional cataract wound and lesser post operative

complications. Coonan et al and Wetzig et al showed reduction of

cystoid macular edema and retinal detachment by keeping posterior

capsular intact3.

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PC IOL constituted the first generation but gave way to ACIOL and

iris fixating IOLs. But PCIOL again captured the centre stage5.

PCIOL forms the VII generation of IOL with refinement like

multifocal, accommodative capacity5.

ECCE method was refined by many pioneers. William Simcoe

introduced the 23-gauge irrigating cannula with suction by syringe.

He popularised the ‘grasp’ method of nucleus delivery. McIntyre and

James Gill are the pioneers of ECCE movement. The introduction of

the anterior chamber maintaining viscoelastic gel, hyaluronic acid

contributed to safer and more highly successful surgery3.

Charles Kelman (1967) introduced Phacoemulsification of the

cataract through a small wound3. But initially the procedure failed to

catch on due to high rate of complications like corneal edema,

vitreous loss and technical difficulty3. The final flaw was in the lack

of ideal IOL which was corrected in the coming years1. The

innovative idea of new capsulotomy like capsulorrhexis advanced the

safety of phacoemulsification. The resurgence of phacoemulsification

was facilitated by the nucleus manipulation techniques and the

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Smaller phacoemulsification probes and foldable implants allowed

the surgeons quest for astigmatically neutral surgical wounds. Girard

was the first to name and describe the scleral tunnel3.

An innovative technique was developed by surgeons to retain the

advantages of phacoemulsification with the need to invest in

equipments. They replaced the mechanics of phaco machine by

modifying the incision architecture and nucleus manipulation. This

technique is described by various terms like manual small incision

surgery, Nonphaco small incision surgery. The cost of the surgery is

reduced significantly by manual methods and use of 6.5mm PMMA

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REVIEW OF LITERATURE

MANUAL SMALL INCISION CATARACT SURGERY

MSICS is an alternative surgical technique that developed after

phacoemulsification. It is a safe, simple, consistent, stable, and

cost-effective way of cataract removal6. In this technique the whole nucleus,

or the nucleus divided in parts, is removed through a self-sealing

sutureless tunnel incision42.

In our country due to the earlier occurrence of cataract and the delay in

seeking treatment, mature and hypermature lenses account for a

significant proportion of cataract cases16. We come across dense brown

and black cataracts associated with Pseudo exfoliation and subluxation,

where manual small incision surgery will be a better option18. Even in the

most experienced hands and in the best operative settings,

phacoemulsification is difficult and prone to complications in eyes with

mature white cataracts16. Therefore it is prudent to consider manual small

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METHODS

Classic Blumenthal technique uses the ACM (Anterior chamber

maintainer) to allow all steps to be performed under positive irrigation

pressure61. It is modified later and is highly effective and reproducible for

all grades of cataract36.

The Ruit technique is well-known modification of MSICS, used in

developing countries36. This technique uses temporal scleral tunnel

straight incision of 6.5 – 7mm incision61.

VARIATIONS IN INCISION

Wound construction plays a major role in MSICS and has to be carefully

planned depending on the technique and type of cataract and the amount

of astigmatism6. By changing the configuration self sealing nature is

imparted to the wound. This prevented the suture related complication.

The most common cause of post operative visual impairment is

astigmatism14. The astigmatic neutral wound became the goal of incision

modification.

Kratz (1980) introduced posterior scleral incision to improve wound

healing and reduce surgically induced astigmatism68.

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Singer (1991) described frown incision to reduce surgically induced

astigmatism61.

Gokhale and Sawhney (2005) studied induced astigmatism with three

scleral incision locations. Their study found induced astigmatism was

lower in the temporal and Superotemporal groups than in the superior

group14.

Lam (2009) modified the incision into large temporal scleral tunnel with

scleral pocket incision with frown configuration.

OPTIMUM INCISION ARCHITECTURE

The incision can be straight, smile shaped, chevron and frown shaped6.

The scleral tunnel incision has three dimensions.

1. The thickness of flap is one third to half the thickness of sclera.

2. The width is the distance from the scleral groove to the point of

entry into the anterior chamber. If it is equal to the length it forms a

square wound and least astigmatism inducing6.

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MANAGEMENT OF NUCLEUS

ANTERIOR CAPSULOTOMY

The MSICS techniques have the nucleus prolapsed into the anterior

chamber as a common step47. The nucleus may be rotated into anterior

chamber or picked by a 26-gauge cystitome. The technique of nucleus

prolapse depends on the type of capsulotomy58.

Following a Can-opener capsulotomy, the nucleus is prolapsed

mechanically without hydroprocedures58. A 26-gauge needle or cystitome

is used to perform anterior capsulotomy47. The Sinskey hook or the lens

dialer is used to lift the superior pole of nucleus and prolapse over the

iris. Then it is rotated in a clockwise or in an anti-clockwise so that the

whole nucleus is out. But the advantage of in-bag IOL is lost in

Can-opener capsulotomy58.

Continuous curvilinear capsulorhexis (CCC) developed by Gimble and

Neuhan allows MSICS to retain the advantages in-bag IOL fixation74, 58.

The intact rim prevents extension of anterior capsular tear into posterior

capsule and provides better centration of IOL74, 25. The elastic margins of

the rim allow the safe expression of nucleus58. The right size of CCC is

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5mm58. Trypan blue staining of the anterior capsule helps in getting an

optimum size CCC in mature and hypermature cataract cases49.

HYDROPROCEDURES

These procedures are manipulations of the nucleus inside the bag58.

Mastering these techniques allows the surgeon to prolapse the nucleus

without altering the pupil size and utilizes single instrument. This reduces

instrumentation and surgical time. These techniques are not safe in eyes

with very hard cataract or weak zonular support58.

Hydrodissection was introduced by Faust and modified by Fine74. This

procedure separates the nucleus from the cortex and the capsule. The

fluid is injected under the lens capsule which cleaves the cortex from

posterior capsule and mobilizes the nucleus.

Hydrodelineation introduced by Anis separates the outer epinucleus shell

from the inner compact endonucleus74. In this fluid is irrigated forcefully

into the nuclear mass giving rise to ‘golden ring’ sign. This reduces the

size of nucleus significantly so that nucleus extraction through the tunnel

incision becomes feasible58.

VARIATION IN NUCLEUS DELIVERY

The extraction of nucleus is the hardest and most critical part of the

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Sandwich technique: the anterior chamber is filled with viscoelastic

material and the nucleus is extracted by sandwiching it between the

irrigating vectis and iris spatula61, 47.

Fish hook technique: this technique was developed by Lahan

(1997)42.The nucleus is delivered by using a bent 30-gauge needle tip or

an irrigating vectis47.

ACM and Sheets glide: this technique is used in Blumenthal MSICS. The

lens glide is placed under the nucleus and gentle pressure on the sclera is

applied. This opens the wound and pushes the nucleus through the tunnel

by the hydrostatic pressure provided by the anterior chamber maintainer36,

61 .

Sinskey hook method: two Sinskey hooks are introduced through two

separate paracentesis. Left hand hook is slipped under the CCC and

elevates the superior pole toward the incision. The right hand hook is

placed beneath the elevated pole prevent the nucleus from falling back

into the bag61.

Viscoexpression: a curved cannula is then insinuated under the nucleus

and the viscoelastic injected beyond the inferior margin of the nucleus.

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gently depressed with the same cannula. This allows the tunnel to open

up and allow the nucleus to be expressed out slowly26.

Irrigating cannula method: Ruit technique of MSICS utilizes this method.

An irrigating Simcoe cannula that was designed with a 26-gauge infusion

and a corrugated concave edge was used. It is used to hydro dissect,

loosen and float the nucleus into the mouth of the tunnel and the nucleus

is expressed out64.

Manual phaco fracture: the scleral tunnel is made large enough to lodge

the nucleus by using the ‘chevron’ frown incision. The lodged nucleus is

manually fragmented and removed through the incision. The endothelial

damage is prevented by breaking the nucleus in the tunnel and

astigmatism is reduced by using ‘chevron’ frown incision61.

Nucleus bisection and trisection: the nucleus is divided into two by using

one instrument as the cutter and vectis as the board47. The nucleus

trisection method described by Kansas and Sax splits the nucleus into

three fragments manually using Kansas trisector and vectis. The resulting

small fragments are viscoexpressed through the small incision61. The

frequent complication is transient corneal edema due to the manipulation

(26)

Snare technique: a wire loop stainless steel snare is used to snare the

nucleus into fragments and expressed through the incision. It is a single

instrument with two cannulas with the wire loop in the tip of the first

cannula. The wire loop is lassoed around the nucleus and divides into two

pieces by constricting47, 61.

VISUAL OUTCOME OF MANUAL SMALL INCISION

CATARACT SURGERY

The outcome of cataract surgery depends on many factors like

preoperative ocular status, quality of surgery, and the postoperative

correction of refractive error51. Good patient selection is an important

determining factor of final visual outcome51. Pre-operative evaluation of

the patient allows the surgeon to select the appropriate technique in

individual case basis.

The WHO defines visual impairment as vision less than 3/6064.The

impact of cataract surgical services are assessed by number of blind

persons (visual acuity <3/60) who regained vision after cataract

surgery51.The quality of cataract services is assessed by the postoperative

vision 51.

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uncorrected visual acuity in at least 80% of surgeries, and ‘poor’ outcome

in less than 5%42.

TABLE 1: WHO GUIDELINES AND RECOMMENDATIONS FOR

THE POST-OPERATIVE OUTCOME OF CATARACT SURGERY

WITH IOL42

GRADE V/A UCVA BCVA

GOOD 6/6-6/18 80% 90%+

BORDERLINE <6/18-6/60 15% <5%

POOR <6/60 <5% <5%

Various studies different parts of world have been published on the

visual outcome of MSICS, comparing with ECCE and

Phacoemulsification. They have proved that MSICS provides better result

than ECCE and comparable results with Phacoemulsification.

Hennig A, et al52 study reported an uncorrected good visual acuity

(≥6/18) in 76.8% of cases at discharge, which declined to 70.5% at

6-weeks and 64.9% at 1-year follow-up. The best corrected good visual

acuity (≥6/18) was found in 96.2% at 6-weeks and in 95.9% of cases at

(28)

Khan M T, et al15 study reported an un-corrected good visual acuity

(≥6/18) in 64% of cases at discharge and in 66.3% of cases at 6-weeks.

The best corrected good visual acuity (≥6/18) in 80.6% of cases at

6-weeks follow-up.

Zaman M, et al46 study reported an uncorrected good visual acuity

(≥6/18) in 62.51% of cases at 1st post-operative day and in 93.40% of

cases at 6-weeks follow-up.

Venkatesh R, et al76 study reported uncorrected good visual acuity

(≥6/18) in 78.4% of cases and best corrected good visual acuity (6/18)

in 97.1% of cases on 40th post-operative day.

MSICS Versus ECCE

Gogate P M, et al17 is a randomized controlled study compared the

efficacy of manual small incision cataract surgery with conventional

ECCE. At 6-weeks follow-up in MSICS group 47.9% of cases had an

uncorrected visual good acuity (≥6/18) compared to 37.3% of cases in

ECCE group. Best corrected visual acuity in MSICS group was good

(≥6/18) in 89.8% of cases compared to 86.7% in ECCE group.1.1% of

cases in ECCE group and 1.7% of cases in MSICS group had

poor(<6/60). In spite of requiring similar equipments to ECCE gives

(29)

In a Cochrane review54, 55, and 56 of surgical interventions for age related

cataract Meta -analysis of two studies, Pune Study and George 2005 was

done to compare MSICS with ECCE. These studies have shown a

significantly better uncorrected visual acuity (≥6/18) and surgically

induced astigmatism in the MSICS group (47.9%) versus ECCE group

(37.3%), but no difference in BSCVA between the two groups.

Venkatesh R, et al49 study reported an uncorrected good visual acuity

(≥6/18) in 87.9% of cases. This study evaluated the efficacy of MSICS in

phacolytic glaucoma cases. The significance of this report lies in the fact

that phacolytic glaucoma is not an uncommon presentation in a

developing country like India49.

MSICS Versus PHACOEMULSIFICATION

Ruit S, et al64 study reported an uncorrected good visual acuity (≥6/18) in

89% of cases in MSICS group and in 85% of cases in the phaco group at

six months follow-up. The best corrected good visual acuity (≥6/18) was

reported in 98% of cases in both the MSICS and the phaco group. The

two groups showed no statistically significant difference in UCVA or

(30)

Venkatesh R, et al16 study reported an uncorrected good visual acuity

(≥6/18) in 82.0% of cases in MSICS group and in 87.6% of cases in the

phacoemulsification group at 6 weeks follow-up.

Singh S K, et al40 study compared the uncorrected visual acuity between

MSICS and phacoemulsification on the first post-operative day. The

study showed an uncorrected good visual acuity (≥6/18) in 77.7% of

cases in MSICS group and in 68% of cases in the phaco group.

Better vision on first post-operative day with MSICS can be correlated

with the greater increase in corneal thickness in the

phacoemulsification64. There is no statistically significant difference

between visual outcomes at 6 weeks follow-up16, 64.

In a Cochrane review54, 55, and 56 of surgical interventions for age related

cataract Meta -analysis of the two studies Gogate 2005 and George 2005

was done. This study reported that that the phaco group has a

significantly improved proportion of patients with an uncorrected good

visual acuity (≥6/18) in 81.1% of cases compared to MSICS group. But

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SURGICAL-INDUCED ASTIGMATISM

Astigmatism means “without a point”. Miller Stephen J defined

astigmatism as a condition of refraction in which a point of light cannot

be made to produce image upon the retina by a correcting spherical lens1

Any ocular surgery with incisions placed on cornea and sclera will induce

astigmatism by altering the curvature of the refracting surface32. The

astigmatism induced by the surgical manoeuvring and the wound healing

is called surgically induced astigmatism. It is a major cause of functional

disturbance and insufficient uncorrected visual acuity20, 31.

Calculating the surgically induced refractive change is important in

evaluating the outcome of small incisions and various wound closures for

cataract surgery4.

The calculation and analysis of various techniques help to determine the

optimal wound size for a cataract surgery4.

With the advent of PCIOL, microsurgical instruments and microscope the

goal of cataract surgery has become the best and earliest possible visual

rehabilitation. Here the best possible vision means best uncorrected visual

acuity19. The biggest hurdle in this quest is the astigmatic component of

(32)

Incision location, length, configuration, closure technique, and

pre-existing astigmatism are some of factors that determine the post-operative

astigmatic error19, 18.

FACTORS RELATING TO INCISION

Self sealing scleral tunnel incisions are less likely to induce astigmatism

because of their posterior (external end) location, anterior corneal

(internal flap) location and the ‘blocking effect’ of the limbus on corneal

astigmatism induction19. The incidence of SIA is more in corneal

incisions because of their anterior location15.

The cataract wound tends to flatten the corneal meridian along which the

wound is centered6. The degree of flattening varies with the site, length

and is predictable to some degree7. Thus postoperative astigmatism can

be controlled by manipulating the site and size7.

Akura J, et al(2000) study evaluated the results of modifications of large

self-sealing incisions in minimizing the SIA7. The BENT (between nine

and twelve-o clock position) frown incision achieved the astigmatic

neutrality and incisions in steeper axis reduced SIA in all cases7.

Merriam J C, et al (2001) study compared the change in corneal

(33)

magnitude and duration of change depend on both length and location of

the incision33.

Gokhale N S, et al (2005) study evaluated the reduction in astigmatism in

MSICS through change in incision site. The SIA was found to be lower in

temporal and super-temporal group compared to superior group14.

Siddique M, et al (2009) study compared the SIA between different

incision sites. The study found that minimum and safe astigmatism is

achieved in temporal approach50.

Venkatesh R, et al (2009) study compared SIA of superior approach with

temporal approach. The study reported 1.08 D in superior and 0.72 D in

temporal group76.

Pawar V S, et al (2012) study compared postoperative astigmatism in

different location and same sizes were compared32. The SIA of temporal

and supero-temporal group was found to be the least32.

Malik V K, et al (2012) study compared the astigmatism in MSICS with

superior and temporal approach. The temporal approach had the lesser

SIA than that of superior65.

Buzard K A, et al (1991) study found no statistically significant

difference in the induced astigmatism between the horizontal suture

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Phacoemulsification is considered superior to manual small incision

cataract surgery due to the smaller incision size and in amount of induced

astigmatism17.This disadvantage can be minimized by altering the

location and configuration as shown in various studies.

The difference in the amount of astigmatism when comparing the

different techniques is relevant in populations that have limited access to

spectacles54, 55, and 56

In a Cochrane review54, 55, and 56 of surgical interventions for age related

cataract Meta -analysis of two studies, Pune Study and George 2005 was

done to compare MSICS with ECCE. The SIA was found to be lower in

MSICS compared to ECCE due to Sutureless wound.

In a Cochrane review54, 55, and 56 of surgical interventions for age related

cataract Meta -analysis of the two studies Gogate 2005 and George 2005

was done to compare MSICS with phacoemulsification. Even though

there was no difference in the average SIA between MSICS and PHACO,

significantly less number of patients had <1 D astigmatism in PHACO

group.

Many studies conclude that although phacoemulsification reduces

astigmatism better than MSICS at 6-weeks follow-up, there is no

(35)

The astigmatism induced in MSICS can be used to neutralize the

pre-existing astigmatism by changing the site of incision18, 65. But this method

has a limited effect in astigmatic reduction- with a maximum reduction of

around 1.00 to 1.50 diopters7.

COMPLICATIONS

MSICS is more difficult than conventional ECCE. The preparation of

optimum size scleral tunnel, handling of instruments, and removing of

nucleus all require better skill and additional training52. The manoeuvring

in the anterior chamber demands good dexterity and surgical skill47. Once

the technique is mastered the surgery is faster and the complication rate is

low52.

The principles of a good MSICS surgery are proper construction of the

scleral tunnel, minimal handling of tissues (cornea, iris), and preserving

the posterior capsule47.

The Oxford Cataract Treatment and Evaluation Team(OCTET) protocol

categorizes the intra-operative and post-operative complications into

three grades17.

Grade I: Trivial complications that may have needed medical

(36)

Grade II: Intermediate complications are that needed medical

intervention. They would have reduced the post-operative vision if left

untreated.

Grade III: Serious complications are that would have needed immediate

medical or surgical intervention. The interventions are a must to prevent

gross visual loss.

INTRAOPERATIVE COMPLICATIONS

• Related to the wound

Shallow tunnel - button holing

Deep tunnel-premature entry, iris injury, and bleeding

Iris prolapse –iris injury, chaffing

Shallowing of AC due to efflux of fluid through the wound

• Sphincter tear due inadequate mydriasis

• Iridodialysis

• Descement membrane stripping and tears

• Striate keratopathy

• Capsulotomy related

Too small – nucleus prolapse difficulty

(37)

• Difficulty in nucleus prolapse –inadequate Hydroprocedures

• Nucleus delivery difficulty due to large and hard nucleus

• Zonular disruption with or without vitreous loss

• Corneal endothelial damage

• Posterior capsular rent with or without vitreous loss

• Incomplete cortical wash- residual cortex at 12-o clock

• Failure to implant due to poor PC support

A complete pre-operative evaluation of individual cases allows the

surgeon to select the appropriate technique and plan the surgical

steps in advance. This ensures a good surgery and spares the

surgeon from unpleasant surprises on the table.

The management of intra-operative complication is made easier by

earlier identification and prompt action. A properly constructed

scleral tunnel incision prevents all the wound related

complication47.

Capsulorhexis of adequate size (>6mm) and Hydroprocedures will

ensure uneventful nucleus prolapse. The staining of anterior

capsule with Trypan blue helps in completing the capsulorhexis 49.

Inferior Iridodialysis is a unique complication of phaco sandwich

(38)

POST-OPERATIVE COMPLICATIONS17, 47

• Striate keratopathy

• Descement membrane folds

• Transient corneal edema

• Shallow AC

• Wound leak

• Hyphaema

• Iritis

• Residual 12-o clock cortex

• Vitreous in AC touching or not touching the cornea

• Pupillary block glaucoma

• Pupillary capture

• Malposition of IOL

• Deposits on IOL

• Posterior capsule opacification

• Cystoid macular edema

• Endophthalmitis

If the proper wound integrity is not maintained, shallowing of AC is seen

on first post-operative day. Whenever there is a doubt about the integrity

(39)

The corneal edema is usually transient and clears off within one week.

Excessive handling of iris will result in post-operative Iritis and cystoid

macular edema47.

Posterior capsular opacification can be prevented or delayed by good

cortical wash and polishing the capsule47.

MSICS is a safe surgery13, 17, 47. Various studies have shown that the

complication rate of MSICS is lower than ECCE and comparable to

phacoemulsification 13, 16, 40, 61, 62.

ADVANTAGES OF MANUAL SMALL INCISION CATARACT SURGERY IN INDIA

Blindness affects an estimated 12.5 million people in India, with cataract

contributing to 50-80% of this49. As the incidence increases with age the

cataract blindness burden will increase significantly due to greying of

population2. The increasing backlog of cataract blindness is the greatest

challenge in cataract surgery48.

To tackle this challenge we need is an efficient, high volume system

utilizing low cost, low technology procedure that can treat advanced

cataracts with minimal complication in the shortest amount of time 42, 48,

(40)

MSICS is considered as the most appropriate technique for performing

high-volume cataract surgery due to its efficiency, safety, shorter surgical

time and lower cost61.

Cataract surgery is considered to the most cost effective medical

intervention. Lansingh V C, et al (2007) determined the

cost-effectiveness of cataract surgery worldwide57. Phacoemulsification was

found to be costlier than either ECCE or MSICS. Since MSICS provides

better uncorrected visual acuity with the same cost, it is considered to be

the most appropriate procedure to tackle the backlog of cataract cases61.

The shorter surgical time of MSICS enhances the productivity of the

(41)

TEMPORAL MANUAL SMALL INCISION CATARACT

SURGERY

Temporal SICS is a type of manual small incision cataract surgery done

through temporal approach.

Cataract surgery is constantly evolving46. Cataract surgery has come a

long way from susrutha’s couching to phacoemulsification74. The

temporal approach was used in couching since it provided the better

access to the patient and the sitting arrangement of the surgeon in front of

the patient 74. The surgeon had to be ambidextrous to operate in both

eyes21.The site of incision shifted to superior when surgery was done with

the patient in supine position74.

With the invention of surgical microscope and intraocular lenses, modern

cataract surgery evolved into a refractive surgical procedure capable of

improving the best uncorrected vision19.

In the quest to achieve best possible post-operative vision, the cataract

surgeons improvised the technique by various modifications. One such

(42)

ADVANTAGES OF TEMPORAL APPROACH

VISUAL OUTCOME

Temporal incision is further away from the visual axis of the eye than the

superior incision. Any resulting corneal edema in postoperative period

will not affect the immediate visual rehabilitation. The wound

construction is done easily in deep sockets and small eyes32.Wound

healing is better in temporal incisions due to the absence of distractive

force of blinking33.Gravity will not interfere with the wound healing and

stability because the wound is parallel to the vector of forces32, 33.

Temporal incisions induce less SIA than superior because of the lesser

influence of lid and the extra ocular muscle7.The mean induced

astigmatism with temporal incisions is 0.75 D, whereas in superior

incisions it is 1.75 D75. Typical human cornea is 1mm wider in

horizontal meridian than the vertical meridian75. Thus the temporal

incisions are placed slightly away than the superior incisions33. Temporal

incisions cause less change in corneal curvature than comparable superior

incisions32. So the SIA is less in temporal incisions32. Temporal small

incision minimizes the senile against the rule astigmatism31, 37, and 45 by

(43)

COMPLICATIONS

The complication incidence is less in temporal manual small incision due

to various factors. It provides better access to instruments and thus

reduces the surgical time36.It is safe in brown and hard cataracts due to its

larger wound size. The larger size may induce more astigmatism, which

is overcome by its placement away from cornea. The temporal manual

small incision cataract surgery utilizes the similar steps in nuclear

management as that of phacoemulsification. The trauma to corneal

endothelial cells is minimal through temporal approach.

ADDITIONAL ADVANTAGES

The superior conjunctiva is left intact which can be used for

trabeculectomy in future, if needed32.Temporal approach cataract surgery

can be done on a eye with filtering bleb32.Temporal approach can be used

as a component in 2-site technique in combined surgery in treatment of

patients with cataract and primary open angle glaucoma9.

SURGICALLY INDUCED ASTIGMATISM

Even though it has been known that cataract incisions influence

astigmatism for long time, only for past 15 years the attention has been

given to the control measures of astigmatism 33, 77. The modern cataract

(44)

of correcting both the spherical and astigmatic components of

refraction19.

Some degree of naturally occurring astigmatic error is said to be present

in nearly 95% of eyes. The clinically significant astigmatism is reported

to occur in 7.5% to 75% of eyes77. The postoperative astigmatism greater

than 2 D occurs in 25 to 30% of eyes77.

The goal of refract cataract surgery has become the correction of

spherical component and eliminate the cylindrical component of

refractive error simultaneously. This is achieved by utilising the biometry

to predict the exact spherical component and by imparting the astigmatic

control measures19. The astigmatic control measures includes the wound

construction to attain least induced astigmatism and exploiting the

astigmatism inducing property of incision to correct the pre-existing

astigmatism18.

The scleral tunnel incisions provide a good control over the induced

astigmatism and faster wound stability34. The pre-existing astigmatism is

neutralized by placing the incision along the steeper axis18.

Senile cataract is most important cause of reversible blindness in India

(45)

astigmatism in the elderly population37, 45. The incision placement at the

steeper axis, the horizontal axis neutralizes the pre-existing error18.

Various studies have proved temporal scleral tunnels are less astigmatism

inducing than the superior tunnels due the minor changes in keratometry,

localised incision flattening, distance from the visual axis.

In patients with mature hard cataract and deep set eyes accessibility

becomes a major problem where temporal SCIS will be better. In

temporal SICS the superior conjunctiva is left undisturbed and can be

utilized for trabeculectomy if need arises. This is advantageous in a case

scenario where the patient has cataract surgery before developing

glaucoma because cataract occurs earlier in our country.

Phacoemulsification is considered to be the gold standard of cataract

surgery 100% phaco is neither practical nor feasible in our country. Even

the experienced phaco surgeons had to be bailed out and conversion to

MSICS gives better visual outcome than ECCE70. This conversion rate is

reported to be 3.7%.

Thus Temporal SICS is not so much as an alternative to

phacoemulsification and superior MSICS but is an additional technique in

the armamentarium. All three techniques are complementary to each

(46)

CASE STUDIES

Many studies have proven the advantage and efficacy of small incision

cataract surgery using temporal approach61.

A prospective randomized clinical trial of phacoemulsification versus

MSICS by Ruit S, Tabin G, Chang D, et al proved that MSICS by

temporal approach gave equally excellent visual outcome as

phacoemulsification. MSICS was significantly faster, less expensive and

less technology dependent than phacoemulsification64.

Singh V K, Winter I, Surin L, et al compared the safety and efficacy of

SICS with temporal approach and phacoemulsification. The study

concluded that SICS with rigid PMMA lens is a suitable technique to

treat immature cataract in developing countries40.

Kongsap P, et al compared Ruit technique was compared with the

modified Blumenthal technique and concluded that both have equal

visual outcomes, with low complication rates36.

Junejo S A, et al concluded that the Nonphaco Sutureless cataract

extraction through temporal approach ensures rapid visual recovery with

(47)

Malik V K, et al concluded that SICS with temporal approach provides a

better stabilization of the refraction with significantly less SIA compared

to superior approach65.

Siddique M, et al compared the visual outcome between superior and

temporal approach in MSICS and concluded that both are safe and

effective. Also the temporal approach provides better un-corrected visual

acuity and least and safe astigmatism50.

Zawar S V, Gogate P, studied the safety and efficacy of temporal manual

small incision cataract surgery in India. The study concluded that

temporal manual small incision cataract surgery gives excellent visual

outcome with minimal astigmatism and low complication rate at

economic cost.

Gokhale N S and Sawhney S study found that induced astigmatism was

lower in temporal and supero-temporal groups compared to that in

superior group14.

Pawar V S and Sindal D K compared the post-operative astigmatism in

small incision cataract surgeries with superior, super-temporal and

temporal incisions. The clinical study concluded that SICS with temporal

and super-temporal incisions provides better quality of vision due to a

(48)

AIM OF THE STUDY

The aim of the study is to

To evaluate visual outcome of Temporal Manual Small incision Cataract

Surgery

To evaluate the intra-operative complications and their management.

To evaluate the post-operative complications and their management.

To assess the visual rehabilitation of the patients after cataract surgery

(49)

MATERIALS AND METHODS

STUDY DESIGN

A prospective hospital based study

SETTING

The study was conducted at the Department of Ophthalmology,

Coimbatore Medical College Hospital.

DURATION OF STUDY

From October 2011 to September 2012

STUDY POPULATION

Adult patients in the age group between 45 to 70 years with senile

cataract who have been operated in the department of ophthalmology

CASE SELECTION

The cases were selected those cases who were operated on two days a

week, on the author’s theatre day. The following inclusion and exclusion

criteria were applied in case selection. Similarity between cases was

maintained as far as possible.

INCLUSION CRITERIA

(50)

Senile immature cataract

Senile hypermature cataract

Nuclear sclerosis 1-4

EXCLUSION CRITERIA

Cases that have not come for 6 weeks follow-up

Cases with pterygium

Cases with corneal pathology

Cases with very high astigmatism>2D

Cases with co-existing glaucoma

Cases with uveitis

Subluxated lens

Traumatic cataract

One eyed patients

(51)

STUDY DESIGN

Case selection is done using the above mentioned inclusion and exclusion

criteria. Demographic details of the cases were recorded.

All the cases were evaluated using the routine preoperative evaluation

protocol by the author. The protocol is as follows:

1. Visual acuity with pinhole

2. Intraocular pressure

3. Syringing of NLD

4. Ruling out of any foci of infection

5. Fundus examination (dilated pupil with IDO)

6. Slit lamp examination for nucleus grading

7. Keratometry

8. A Scan biometry

9. Blood pressure

10. Urine sample for sugar and albumin

11. Random blood sugar

All the selected cases were operated by a single surgeon, who is well

(52)

and in both approaches, superior and temporal. This is done to avoid the

compounding effect of the surgeon factor.

All were operated under peribulbar anaesthesia using 3ml of 2%

xylocaine with adrenalin 1:1000 dilution mixed with Bupivacaine. Two –

needle technique was used.

PERIBULBAR ANAESTHESIA

The adjective peribulbar refers to that location external to confines of the

four muscles and their intermuscular septa8. Local anaesthetic agents are

deposited within the orbit but do not enter within the geometric confines

of the cone of rectus muscles8. The intermuscular septum was incomplete

and permitted anaesthetic solution to spread into the cone8. Of the many

variations of technique a common one is two-needle technique. In this

first injection is given in inferior-temporal and the second in superior

nasal quadrant8. Up to 5ml of

Anaesthetic solution is given. Peribulbar block is safer than the traditional

retrobulbar anaesthesia as it avoids injury to optic nerve and extracular

muscles. Delayed onset of akinesia, requirement of greater volume of

anaesthetic solution leading to increased ocular pressure, periorbital

ecchymosis and conjunctival chemosis are the main complications of

(53)

SURGICAL TECHNIQUE

The position of the surgeon and the assisting staff is important in

temporal small incision cataract surgery. The surgeon was seated right

side of operating table for right eye cases and the assisting staffs were

placed at the head end. This positioning was changed accordingly in left

eyes.

Since this rearrangement was time consuming, the cases were selected in

such a way that one(R/L) sided cases were operated on one day.

Eyelid and surrounding area cleaned using povidone iodine solution and

draped with eye towel. A wire speculum applied and conjunctival

irriagation with povidone-iodine solution was completed.

Superior rectus bridle suture was not required, which saved time and

prevented any untoward injury to the muscle sheath.

A limited peritomy and light wet field cautery done.

CONFIGURATION OF THE INCISION

A 6-7 mm external scleral straight incision, 2mm behind the limbus was

created using an 11-blade. The depth of incision was ½ of scleral

(54)

The crescent blade was used to dissect the scleral lamellae and scleral

tunnel was created. The tunnel was extended 2mm into the clear cornea.

The internal opening of the sclerocorneal tunnel was made using 2.8 mm

keratome knife in a downward angle. By this angulation three plane of

the incision was maintained. A side port was created 90° away from the

tunnel.

CAPSULORHEXIS - CCC

The anterior chamber was filled with viscoelastic (2% hydroxyl propyl

methyl cellulose). The capsulorhexis of size more than 6mm was

completed using the bent 27-gauge needle. The internal lip of tunnel was

extended full length using blunt 3.2mm extending knife.

NUCLEUS PROLAPSE AND DELIVERY

Hydroprocedures were done and nucleus was prolapsed into the AC with

the bent 27-gauge needle. The viscoelastic material was filled in the AC

and the nucleus was extracted with the phaco-sandwich technique.

Phaco-sandwich is a two-instrument technique. The prolapsed nucleus is

sandwiched between the vectis and iris spatula to deliver out. A

complication peculiar to this technique is inferior Iridodialysis.

(55)

CORTICAL WASH AND IOL IMPLANTATION

A complete cortical wash was done using simcoe irrigation aspiration

cannula. Viscoelastic material was injected into AC and the capsular bag

was inflated.

The rigid 6.5mm PMMA IOL was implanted in the capsular bag. The

visco elastic material was removed by irrigation and aspiration with

Simcoe cannula.

WOUND CLOSURE

The wound was closed with inflating the AC with ringer lactate solution

via the side port. The self-sealing nature of wound was checked at the end

of procedure. No sutures were applied and conjunctiva was opposed with

light cautery.

All the cases were given subconjunctival 0.5ml gentamycin and 0.5ml of

dexamethasone. Sterile pad and bandage was applied.

The intra-operative complications and the duration of surgery were

documented for all surgeries.

I POST-OPERATIVE DAY EVALUATION

1. Wound approximation

(56)

3. Slit-lamp examination - cornea, AC reaction, IOL position

and complications if any.

4. Fundus examination

All the patients were treated with topical ciprofloxacin and

dexamethasone eye drop every two hours on I post-op day.

The topical ciprofloxacin and dexamethasone eye drops six times

per day were given to all the patients for one week.

I WEEK FOLLOW-UP

1. Wound integrity

2. Visual acuity with pinhole

3. Slit lamp examination –cornea, anterior segment reaction, IOL

positioning, and complication if any.

The antibiotic steroid combination drug dose was tapered gradually to

twice per day in six weeks. Corneal edema and fibrinous uveitis are

treated medically.

6 WEEKS FOLLOW-UP

1. Visual acuity- best corrected vision

2. Refraction

(57)

4. Keratometry

5. Fundus examination

6. IOP measurement

Refraction was done after dilating and retinoscopy done using

plane mirror retinoscopy. Keratometry reading were recorded to

calculate the astigmatic change caused by the surgery. Bausch &

Lomb Keratometry and automated refractometry were used for

recording the keratometry values.

KERATOMETRY27

Keratometry is the optical method of determining the curvature of the

central cornea. Usually it is expressed as dioptric power (D) or as dioptric

curvature (Kd) of the cornea. The steepest and flattest curvatures act as

the principal meridians and the dioptric values associated with them are

called K readings.

Normally the K readings of the principal meridians are nearly of same

magnitude, 43D on average and usually within ±0.5D of one another. The

difference in K reading is defined as corneal astigmatism. The differences

more than 0.5D tend to indicate a significant amount of astigmatism,

(58)

Typically, there are three forms of regular astigmatism namely with- the-

rule, against-the-rule, and oblique astigmatism. The with-the-rule is most

common and against-the-rule is less common (except in older adults).

The oblique astigmatism is the least common.

The irregular astigmatism cannot be assessed perfectly with keratometry

alone, because of the distortion of the mire circle. The cases with

irregular astigmatism were ruled out during the case selection in the

present study.

A-SCAN BIOMETRY

It consists of entering K reading with ultrasonic measurement of axial

length. IOL power was calculated using SRK II formula.

METHODS OF STATISTICAL ANALYSIS

The tests used for analysis of this study are the t test and chi-square test.

The p value is calculated and less than .05 has been taken as significant.

Descriptive statistical analysis of this study was done. The measurements

are expressed in number as frequency and percentage.

The relationship between independent variables was analysed by

(59)

RESULTS AND OBSERVATIONS

The study entitled “A Prospective Clinical Study of Temporal Manual

small incision surgery” comprises of total 83 cases.

The age of the cases varies in range of 40 to 80 years. The majority (61%)

of cases were in the age group 50 to 70 years.

TAB – 2 : AGE GROUP

AGE FREQUENCY PERCENTAGE

35- 40 YRS 6 7.2

41-50YRS 7 8.4

51-60YRS 31 37.3

61-70YRS 32 38.6

71-80 YRS 7 8.4

(60)

The study group comprises of 53(63.9%) female patients and 30(36.1%) male patients. SEX MALE FEMALE TOTAL 6 7 0 5 10 15 20 25 30 35 40 45 frequency

35-40 years 41

FIGURE-1

The study group comprises of 53(63.9%) female patients and 30(36.1%)

TAB- 3 : GENDER

FREQUENCY PERCENTAGE

30 36.1

53 63.9

83 100

7.2 8.4 31 37.3 32 38.6 7 frequency Percentage

age in years

41-50 years 51- 60 years 61 - 70 years 71 - 80 years

The study group comprises of 53(63.9%) female patients and 30(36.1%)

PERCENTAGE

38.6

8.4

(61)

Among the 83 cases 28

immature cataract.

TAB 4

TYPE FREQUENCY

SMC 28

SIMC 55

TOTAL 83

30 0 10 20 30 40 50 60 70 Male

FIGURE - 2

Among the 83 cases 28 were senile mature cataract and 55

TAB 4 : TYPE OF CATARCT

FREQUENCY PERCENTAGE

28 33.8

55 66.2

83 100

53 36.1 63.9 Male Female Frequency Percentage

55 were senile

Frequency

(62)

The hardness of the cataract was graded based on the colour of nucleus

under slit-lamp examination.

predominantly found the study group, 52 cases (62.6

found in 19 (22.9%) and grade IV in 12

TAB NUCLEUS GRADE 2.00 3.00 4.00 TOTAL 28 0 10 20 30 40 50 60 70 SMC

FIGURE – 3

The hardness of the cataract was graded based on the colour of nucleus

lamp examination. Grade III nucleus sclerosis was

nantly found the study group, 52 cases (62.6%). Grade II was

in 19 (22.9%) and grade IV in 12 cases (14.5%).

TAB – 5 : GRADE OF NUCLEUS

NUCLEUS GRADE FREQUENCY PERCENTAGE

19 22.9%

52 62.6%

12 14.5%

83 100%

55

33.8

66.2

SIMC

The hardness of the cataract was graded based on the colour of nucleus

nucleus sclerosis was

%). Grade II was

PERCENTAGE

Frequency

(63)

The pre-operative visual acuity was poor <6/60 in

borderline in 11(14.5%). Among the 72 cases 15 of them had <1/60

vision. FIGURE 19 22.9 0 10 20 30 40 50 60 70 2

8 8 8

0 2 4 6 8 10 12 14 16 18 20

1/60 2/60 3/60

FIGURE - 4

operative visual acuity was poor <6/60 in 72cases (86.7%

14.5%). Among the 72 cases 15 of them had <1/60

FIGURE – 5 VISUAL ACUITY (PRE-OP)

52 12 62.6 14.5 3 4 Frequency Percent 7 8 2 9 18

2 3 3

4/60 5/60 6/24 6/36 6/60 CFCF HM + HM+

86.7%) and

14.5%). Among the 72 cases 15 of them had <1/60

Frequency

7

PL+

(64)

All the patients were operated by a singl

sclerocorneal tunnel incision

peribulbar anaesthesia was given to all cases.

The size of the incision was either 6 or 6.5mm depending on the pre

operative evaluation. 55 cases (66.3%) had

the remaining 28 cases (33.7%) had a 6mm incision.

TAB SIZE(MM) 6 MM 6.5MM TOTAL 28 33.7 10 20 30 40 50 60 70

All the patients were operated by a single surgeon. The temporal

sclerocorneal tunnel incision was used in all cases. Two site technique of

peribulbar anaesthesia was given to all cases.

The size of the incision was either 6 or 6.5mm depending on the pre

operative evaluation. 55 cases (66.3%) had a 6.5mm scleral incision and

8 cases (33.7%) had a 6mm incision.

TAB-6: INCISION SIZE (MM)

FREQUENCY PERCENT%

28 33.7

55 66.3

83 100

FIGURE - 6

55 66.3

FREQUENCY

PERCENT

e surgeon. The temporal

technique of

The size of the incision was either 6 or 6.5mm depending on the

pre-ral incision and

FREQUENCY

(65)

The duration of the surgery was recorded with a stop clock

51 cases (61.4%) were operated

completed in 10 minutes and 8 cases (9.6%) in 6 minutes.

to 10 minutes and average duration is 8.355 minutes.

TAB TIME (MINUTES) 6 8 10 TOTAL 8 9.6 0 10 20 30 40 50 60 70 6mts

The duration of the surgery was recorded with a stop clock and tabulated.

61.4%) were operated in 8 minutes.24 cases (29%) were

completed in 10 minutes and 8 cases (9.6%) in 6 minutes. It varies from 6

to 10 minutes and average duration is 8.355 minutes.

TAB – 7: DURATION OF SURGERY

MINUTES) FREQUENCY PERCENTAGE

8 9.6

51 61.4

24 29.0

TOTAL 83 100

FIGURE - 7

51 24 61.4 29 8mts 10mts FREQUENCY PERCENTAGE and tabulated.

in 8 minutes.24 cases (29%) were

It varies from 6

AGE

FREQUENCY

Figure

TABLE 1: WHO GUIDELINES AND RECOMMENDATIONS FOR

TABLE 1:

WHO GUIDELINES AND RECOMMENDATIONS FOR p.27
45FIGURE-1
45FIGURE-1 p.60
 FIGURE - 2
FIGURE - 2 p.61
 FIGURE – 3
FIGURE – 3 p.62
FIGURE - 4

FIGURE -

4 p.63
FIGURE – 5  VISUAL ACUITY (PRE-OP) FIGURE

FIGURE –

5 VISUAL ACUITY (PRE-OP) FIGURE p.63
 FIGURE - 6
FIGURE - 6 p.64
 FIGURE - 7
FIGURE - 7 p.65
120FIGURE – 8
120FIGURE – 8 p.66
 FIGURE – 9
FIGURE – 9 p.68
FIGURE – 10

FIGURE –

10 p.69
FIGURE 11

FIGURE 11

p.70
FIGURE – 12

FIGURE –

12 p.71
FIGURE 14

FIGURE 14

p.75
FIGURE – 15

FIGURE –

15 p.76
FIGURE – 16

FIGURE –

16 p.77
FIGURE – 17

FIGURE –

17 p.79
FIGURE – 18

FIGURE –

18 p.80
FIGURE - 19

FIGURE -

19 p.81
FIGURE – 20

FIGURE –

20 p.82
FIGURE 21: K VALUES

FIGURE 21:

K VALUES p.83
TABLE:21-KERATOMETRY VALUES
TABLE:21-KERATOMETRY VALUES p.84
FIGURE – 22

FIGURE –

22 p.85
FIGURE – 23

FIGURE –

23 p.86

References

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